Unstable fracture dislocations of the proximal interphalangeal joint. Treatment with the force couple splint.

The force couple splint maintains concentric joint reduction while allowing early active range of motion exercises. Sixteen cases were treated with a force couple created across the proximal interphalangeal (PIP) joint, levering the dislocated base of the middle phalanx palmarly, while simultaneously lifting the distal end of the proximal phalanx dorsally to restore joint reduction. The splint is constructed from three Kirschner wires and is activated by a single rubber band. The effect of this force couple is present through a complete range of joint motion, thereby allowing active flexion and extension of the joint during bone and soft tissue healing. The force couple splint is capable of producing good to excellent results in patients with unstable acute fracture dislocations of the PIP joint.